Note 103 — Chapter VIII · PLATONIC COMPOSITIONS GENERALLY.
Reading edition
As an illustration of that class of minds which take delight in the search for truth in different directions, I copy the following passage respecting Dr. Priestley, from an excellent modern scientific biography. “Dr. Priestley had seen so much of the evil of obstinate adherence to opinions which time had rendered decrepit, not venerable — and had been so richly rewarded in his capacity of natural philosopher, by his adventurous explorations of new territories in science — that he unavoidably and unconsciously over-estimated the value of what was novel, and held himself free to change his opinions to an extent not easily sympathised with by minds of a different order. Some men love to rest in truth, or at least in settled opinions, and are uneasy till they find repose. They alter their beliefs with great reluctance, and dread the charge of inconsistency, even in reference to trifling matters. Priestley, on the other hand, was a follower after truth, who delighted in the chase, and was all his life long pursuing, not resting in it.
On all subjects which interested him he held by certain cardinal doctrines, but he left the outlines of his systems to be filled up as he gained experience, and to an extent very few men have done, disavowed any attempt to reconcile his changing views with each other, or to deprecate the charge of inconsistency.… I think it must be acknowledged by all who have studied his writings, that in his scientific researches at least he carried this feeling too far, and that often when he had reached a truth in which he might and should have rested, his dread of anything like a too hasty stereotyping of a supposed discovery, induced him to welcome whatever seemed to justify him in renewing the pursuit of truth, and thus led him completely astray. Priestley indeed missed many a discovery, the clue to which was in his hands and in his alone, by not knowing where to stop.”
(Dr. Geo Wilson — Life of the Hon. H. Cavendish, among the publications of the Cavendish Society, 1851, p. 110-111.)